This invention relates to chain winches of the type for handling anchor chain, and in particular to a chain winch for handling different size anchor chains.
Historically, ships carry only one size anchor chain, not necessarily because of the strength requirements throughout the entire cable length, but rather, because heretofore an anchor chain wildcat could accomodate only one specific chain size. Many ships carry throughout their service life nonessential tons of weight in their chain lockers with attendant loss of useful payload and propulsive power.
Chain, such as anchor chain on ships, is customarily hoisted by a power source developing a rotational force. This force is transmitted to the chain by a specifically configured drum type device called a wildcat secured to the rotating power shaft. The configuration of the wildcat is specifically shaped to the particular size and diminsions of the chain to be handled. The shape consists of whelps or "dogs", which intersperse themselves between the horizontal links (chain having a vertical link alternating with a horizontal link) and which apply force to the rear of each horizontal link as it enters the wildcat. Between the whelps are "pockets" shaped to the dimensions of the horizontal links. These pockets keep the chain at a fixed radius about the power shaft centerline which is based upon the chain link length. If another size chain, having links of different length and width from that for which the wildcat was specifically designed is used, power cannot be effectively applied without having a new and differently shaped wildcat secured to the power shaft.
There are situations where the lifting of a length of chain having different sizes in that length is required. This has been usually accomplished through gripping the chain by a hook from a crane or other lifting device, and through a series of staged lifts in which the hook is reattached down the chain a number of times, the entire chain length being raised. This method is not only time consuming but requires labor personnel placed in a hazardous position.
The following patents are directed to chain hoists where alternated chain links are engaged by whelps of sprocket teeth to lift the chain:
U.S. Pat. No. 2,548,846, issued to Robins et al PA0 U.S. Pat. No. 3,507,471, issued to Haynes et al PA0 U.S. Pat. No. 4,034,556, issued to Riber PA0 U.S. Pat. No. 4,646,805, issued to Dohmeier
While these patents show chain hoists and positive chain link engagement, there is no showing of a wildcat drum to handle a length of chain having different size links. The present invention overcomes the showing of the prior art.